Nonmetallic tie place



United States Patent Charles .1. Pennlno Monroeville, Pennsylvania793,099

Jan. 22, 1969 Dec. 1, 1970 Koppers Company, Inc.

a corporation oi Delaware [72] inventor [21 App]. No. [22] Filed [45]Patented [73] Assignee [54] NONMETALLIC TIE PLATE 4 Claims, 4 DrawingFigs.

[52] U.S.Cl. 238/283, 238/287 [51] Int.Cl. E01b9/40 [50] FieldofSearch238/l,l0, 10(D), 29, 83, 84,107, 151,152, 264, 283, 287, 310,315,382

[56] References Cited UNITED STATES PATENTS 2,950,057 8/1960 Speer 238/83,191,864 6/1965 Moses..... 238/371 3,268,170 8/1966 Moses 238/283 3,289,940 12/ l 966 Groff 23 8/29 3,358,925 12/1967 Pennino 238/2873,369,753 2/1968 Olson 238/283 Primary Examiner-Arthur L, La PointAssistant Examiner-Richard A. Bertsch Attorney-Oscar B. Brumback andOlin E. Williams ABSTRACT: A nonmetallic tie plate is provided which isdisposable on a railroad tie for carrying a rail and which is usablewith railroad spikes for securing the tie, the tie plate, and

the rail together as a unit. The tie plate comprises a high densi- I typolyethylene which is capable of absorbing impact stresses and ofdistributing conventional compressive stresses that are caused by atrain passing over the rail.

NGNMETALLIC Trs PLATE BACKGROUND OF THE INVENTION This invention relatesto a railroad tie plate and more particularly to a nonmetallic tieplate.

In the conventional construction of railroads, a metallic tie platecarrying a rail is disposed upon a surface of a wooden tie to spread anddistribute the load or weight transmitted to the tie from the railsupporting a passing train. conventionally, the tie plate and the railare secured to the wooden tie by spikes driven through holes disposednear the lateral edges of the tie plate. These spikes secure the rail tothe tie plate and likewise secure the tie plate to the wooden tie torestrict horizontal and vertical movements of the rail as the trainpasses over these rails.

Metal tie plates have been used for many years, although they have notbeen completely satisfactory. For example, the wooden tie is subject toplate cutting by the metal tie plate; that is, the cutting or wearing ofthe wooden tie by the tie plate. To reduce plate cutting, the metal tieplates have been made wider in order to more uniformly distribute theload from the rail to the tie. In some instances, tie plates havedimensions up to 16 inches in width, and still the tie plate cuts thewooden tie.

In addition, metallic 1 tie plates have a high modulus of elasticitywith respect to the stiffness modulus of wood; consequently, the tieplates do not absorb the initial shock or impact stresses resulting fromthe passing train, nor absorb sound waves and noise.

I have found a tie plate which is composed of a material which resolvesthe conflicting extremes of adequately transmitting and spreading theload of the passing train yet protecting the spikes from the buffetingof a tie plate and still absorbing sound waves.

DESCRIPTION OF PRIOR ART Several solutions have been proposed heretoforeby those skilled in the art to solve the aforementioned problems. U.S.Pat. No. 3,206,123, RLS. Baker, disposes a resilient polyethylene padbetween a rail and a concrete tie to protect the tie from shock. Onedisadvantage of Baker is that the pad does not'protect the spikesfromimpact stresses. If Bakers teachings were employed with wooden tiesanother disadvantage would be that the pad, being composed of a flexiblepolyethylene, would not distribute the weight from the rail over thesurface of the wooden tie.

US. Pat. No. 2,892,592, John H. Greene, places a flexible tie padbetween a metal tie plate and a wooden tieJA disadvantage, however, isthat the metal tie plate is still required in- Greene and again thespikes are subject to loosening by the horizontal components of motionof the tie plate.

In my patent, U.S. Pat. No. 3,358,925, I provide a nonmetallic tie platecomposed of polyurethane or epoxies. The advantages of my patented tieplate include the bonding of the tie plate to the wooden crosstie toadditionally protect the tie from the entrapment of moisture and dirtparticles between the tie plate and the wooden tie. As a result of thisbonding, the use of spikes is eliminated. However, to some skilled inthe art, the use of spikes as a means of holding the tie plate to thecrosstie is still desirable, particularly where it is wished to be ableto replace the tie plate on the wooden tie.

My invention comprises a nonmetallic tie plate which is useable withrailroad spikes. In fact, the tie plate is not conveniently adhesivelybonded to a tie. The tie plate of my invention is composed of a materialwhich imparts unexpected characteristics to the plate; namely, the tieplate is resilient relative to metallic tie plates and is capable ofabsorbing shock and of abating noise and yet is not so resilient thatthe loads are not transmitted and dispersed over the wooden tie. Becauseof the lower stiffness modulus of my tie plate and due to the design ofmy invention, the railroad spikes are protected from the looseningaction of the tie plate caused when a train passes over a rail; hence,the life of the spike holding a tie plate to the tie is extended and theresetting of railroad tie plates is unnecessary.

SUMMARY OF THE INVENTION In accordance with my invention, the tie platecomprises a right-angled parallelepiped which has a flat bottom surfacefor resting upon a railroad cross tie and has an upper surface spacedapart from the bottom surface. A recessed upper sur face carries a rail;the recess extends from one end to the opposite end of the tie plate anddefines a planar surface that is canted from one side to the oppositeside of the tie plate at a slope of approximately 1 unit of rise to 40units of run with respect to the bottom surface. Shoulders are therebyprovided at each side of the tie plate which shoulders provide an innersurface meeting the planar recess surface for restricting the lateralmovement of the rail carried by the recess. Also provided by theshoulders is an outer surface meeting the flat bottom surface which,when the tie plate is disposed into a recess rabbetted on a tie,restricts the lateral movement of the tie plate with respect to the tieby the outer surface engaging the side walls of the recess in the tie.Slots in each shoulder are spaced at locations on each side of the tieplate, the slots on each side being diametrically opposed and each slotextending from the edge of the plate to the recessed surface of the tieplate for receiving a spike. The tie plate is composed of high densitypolyethylene.

GENERAL DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is an exploded perspective view of the nonmetallic tie plate andthe components with which it cooperates;

FIG. 2 is a cross-sectional view of the nonmetallic tie plate incooperation with a railroad crosstie;

FIG. 3 is a perspective view of the tie plate; and

FIG. 4 is a cross-sectional view of the tie plate.

DETAILED DESCRIPTION OF THE DRAWINGS In FIG. 1, a wooden crosstie isshown generally indicated at 2 to carry the nonmetallic tie plate 6, anda conventional rail 8 which is supported by the tie plate 6 andsecurable by spikes 10 to the tie 2. Generally two such rails aresecured to each tie by a tie plate at spaced apart distances from oneanother to form the gage of the track.

Crosstie 2 has a rectangular recess indicated at 4 transversely cut intothe upper surface 20 of the tie providing sidewalls 40 which extend to adepth of about seven-eighths inches. The depth will depend upon thethickness t of the'tie plate 6 so that the tie plate 6 fits flush withthe upper surface 20 of the tie as shown in FIG. 2.

The nonmetallic tie plate 6, molded as a separate member, is generallyformed as a rectangular slab or a right angled parallelepiped to fitsnugly in the recess 4 between the side walls 40.

The plate has a generally flat bottom surface 60 in FIG. 3 forengagement with the tie 2 in groove 4. The tie plate 6 has an uppersurface, generally indicated at 62, which is spaced apart from thebottom surface 60. The upper surface 62 has a recess generally indicatedat 64 in the upper surface 62 extending from one end of the tie plate tothe opposite end which defines a plane surface 66. This planar surface66 is canted from one side to the opposite side of the tie plate 6 atthe slope of approximately 1 unit of rise to 40 units of run withrespect to the bottom surface 60. The slope of the cant is in accordancewith the standards specified by various railroad companies. The purposeof the cant is to dispose the rails 8 inwardly of the track so that whenthe wheels of a train pass over the rail 8, the load is bettersustained. The tie plate 6 has raised abutments or shoulders 68 at eachside of the tie plate, providing an inside planar surface which iscontiguous with and meets the planar surface 66 of the tie plate 6. Thisinside planar surface 160 restricts the lateral movement of the rail 8when a train passes over the rail as best seen in FIG. 2.

The shoulders 68 also have an outer side planar surface 162 which, whenthe tie plate 6 is disposed within the recess 4 of the tie 2, engagesthe side walls 40 of the tie 2 to prevent and to restrict any lateralmovement of the tie plate with respect to the tie 2. Slots generallyindicated at 164 are provided in the shoulder 68 at spaced locations oneach side of the tie plate 6. These slots 164 on each side arediametrically opposite one another and they extend from the edge of thetie plate 6 or the outer planar surface 162 to the recessed surface 66of the tie plate or to the inside surface 160 of the plate.

The tie plate 6 is disposable within the recess 4 of the tie 2 as seenin FIGS. 1 and 2. The outer planar surfaces 162 of the tie snugly engagethe side walls 40 of the cross tie 2. As shown in FIG. 2, the tie plate6 disposed in the recess 4 is flush with the surface 20 of the tie, sothat there is a coextensive engagement of the outer surface 162 with thesidewalls 40 of the tie. This aspect of the invention is essential aswill be described hereinafter in order to provide sufficient support asthe tie plate is thrust against the sidewalls 40 of the tie. The innerwall 160 of the shoulders 68 are substantially coextensive with thesidewalls 82 of the base portion 80 of the rail 8 to provide supportwhen the base portion 80 is thrust against the shoulder 68 by thepassage of a train over the rail.

The spikes 10 are disposable through the slots 164 of the tie plate 6 toengage the base portion 80 of the rail 8 for holding the rail to the tieplate 6. Conventionally the spikes hold the tie plate to restrainlateral movement of the tie plate with respect to the tie. But inaccordance with my invention the shoulders 68 of the tie plate byengaging the sidewalls 40 of the recess 4 restrain lateral movement ofvthe tie plate; hence the function of the spikeszl in accordance with myinvention is merely to hold the rail 8 in the recess 64 of the tie plate6.

The slots 164 are spaced at locations according to the specificationprovided by the railroad industry. These specifications depend on thetype and size of rail, particularly the cross-sectional width of thebase portion 80 of the rail.

The dimensions of a commercially feasible tie plate are as follows:

The first dimension is referred to in FIG. 3 as the A dimension whichdefines the distance on each side of the tie plate with which the slotsare spaced apart, andthe second dimension, B dimension, is the distancethat the slots are oppositely spaced apart of one another. For instance,with a 132 lbs. rail (a term of the art) which has a 6-inch base widthof the rail 80, the'B dimension is conveniently 6%" from center tocenter of each slot. The A dimension is conveniently 3 h from center tocenter of each slot. As a further example with a l 15 lbs. rail, havinga base width of /z", the B dimension is 6 A and the A dimension is 4".The minimum width w of the shoulder 68 as shown in FIG. 1 will dependupon the maximum diameter of the spike to be used to secure the tieplate 6 and the rail 8 to the tie 2'and also will be determined by thecomposition of the tie plate in order to provide a sufficient width forrestraining lateral movement of the tie plate. Conventionally squarespikes are used having side dimensions of /s"; the minimum width w ofthe shoulders 68 should, therefore, be approximately 4" from the innerplanar surface 160 to the outer planar 162 of the tie plate 6. Thiswidth is also, sufficient to restrain lateral movement of the tie plate6. The minimum thickness (a) from the bottom surface 60 of the tie plate6 to the surface of the recess 66 in FIG. 4 has been found to be 4";however, greater thicknesses will offer the greater protection of thewooden tie. The depth (,8) or the distance from the surface of therecess 66 to the top surface 62 of the tie plate generally 62 willdepend upon the thickness of the base portion 80 or the height of thesidewall 82 of the rail 8, and equal thereto in order that there will bea flush fit between the base of the rail 80 and the upper surface 62 ofthe tie plate 6, and also will depend on the slope or cant ofthe surface66.

The shoulders 68 of the tie plate 6 serve a plurality of functions. Theyrestrict lateral movement of the rail 8 carried by the tie plate 6; theyrestrict lateral movement of the tie plate 6 itself with respect to thetie; and they protect the spikes l0 from loosening due to the buffetingof the tie plate 6 against the spikes 10 that is caused by a passingtrain. Hence the width w of the shoulders absorbs the shock of a suddenload causing a lateral thrust of the tie plate against the side walls 40of the tie as illustrated in FIG. 2. Movement of the tie plate isrestrained by the engagement of the outer wall 162 against the sidewall40. In addition, the tie plate 6 at the edge of the slots 164 facing thesidewall 40 may however engage the spikes 10.

Because the tie plate 6 is composed of a nonmetallic material, 7

the plate absorbs the shock of this engagement which reduces theprobability of loosening the spikes 10.

It is believed that atie is normally subjected to two kinds of stresses:impact stresses and conventional compressive stresses transferred fromthe rail to the tie plate to the tie. .The most damaging stresses arethose of t impact in that they represent a higher concentration ofenergy, causing more severe damage to a railroad tie by the cutting of atie plate than conventional compressive stresses. Of course, compressivestresses may damage a railroad tie by the continuous exertion of a loadon a tie plate g against the tie.

Conventionally the damage caused by compressive stresses on a tie may besubstantially reducedby using wider metal tie plates which are capableof distributingthe stresses over a greater surface of the tie. To someextent, wider tie plates also will distribute the impact stresses causedby the shock of the train passing over the rails. Conventional railroadtie plates are composed of a metal with a high modulus of elasticityrendering the tie plate capableof adequately distributing thecompressive stresses; yet, the impact stresses are still transmittedthrough the tie plate to the tie surface causing severe damage. 1

I have found in accordance with this invention that by using a tie platecomposed of a material which essentially absorbs impact'stresses and yetis capable of distributing compressive stresses resolves the conflict ofcompressive and impact stresses. The material used in my inventionabsorbs impact stresses as well as distributes compressive stresses.

In accordance with my invention I have found that high den sitypolyethylene not only is capable of absorbing the impact stresses butalso is capable of distributing compressive stresses. I have also foundpolyurethanes and epoxy resins not to be suitable for my inventionbecause they are essentially nonflowable materials and, when compared tothe high densi-' ty polyethylene used in my invention, are inelastic.Metallic tie plates are likewise not suitable with my invention becauseagain they are, compared to the high density polyethylene used in myinvention, also inelastic materials.

High density polyethylene is essentially a linear polyethylene asdescribed in US. Pat. No. 2,816,883, Larchar and Pease. Conventionallyhigh density polyethylene is produced at low pressures and lowtemperatures using a Ziegler catalyst. Typical properties of highdensity polyethylene include:

Tensile strength, (yield)30004800 p.s.i. Percent elongation atbreak65230 percent. Stiffness modulus Gin specimen)105,000150,000

p.s.1. Impact strength (Izod)1.515.0 ft.-lbs. per inch.

.Density0.941-0.965 grns./cm.

polyethylene from ultra-violet degradation and to preserve polyethlenefrom weathering. One source of high density polyethylene with a carbonblack filler is Super Dylan 7000-N produced by Sinclair-Koppers Companyhaving the following properties: 1

Tensile strength (yield)3500 p.s.i.

Percent elongation at break250 percent. Stifiness modulus O1specimen)105,000 p.s.i. Impact strength (Izod)3.0 ft.lbs. per inch.l)cnsity0.965 grns. per cc.

Abrasion2.0 mg. per 1000 cycles.

This particular product has approximately 2% percent by weight of carbonblack filler.

The physical properties of the high density polyethylene are improved byreinforcing with glass fibers so the tie plate may better sustain itsloads. By incorporating about 30 percent by 5 weight of glass fibersinto polyethylene the stiffness modulus may be increased to 366,000p.s.i.

The tie plates may be conveniently manufactured by injected moldingtechniques or be conventional compressive molding and subsequentlyfitted into the recess 4 after moldmg.

As an example of the invention, a polyethylene tie plate having a carbonblack filler was molded and positioned into the recess of the tie insimilar fashion to FIGS. l-3. The polyethylene used was Super DylanPolyethylene 70 7000-N having the physical properties previously listed.This construction was then tested in a machine provided for suchpurposes by the American Railroad Association to artificially simulatethe stresses and strains normally encountered in normal service. The tieand my nonmetallic tie plate secured thereto with spikes was thensubjected to 2% million cycles over a period of several weeks whichrepresented a life-time wear of moderate railroad traffic. The rail wasthen removed from the tie and the surface of the tie was examined forwear. The wear on the polyethylene tie plate was very slight, and wearon the tie was also slight.

Thus my invention provides a nonmetallic tie plate composed of highdensity polyethylene which is capable of absorb ing impact stresses yetit is capable of spreading and distributing the load of a passing train.Because the tie plate of my invention is disposed within a recess of atie the spikes are relieved of the function of restricting lateralmovement of my tie plate. The shoulders of my tie plate are engageablewith the sidewalls of the recess to restrain lateral movement of the tieplate. My tie plate being composed of density polyethylene, absorbssound waves thus providing noise abatement. Also my tie plate protectsthe spikes from loosening due to the buffeting of the tie plate againstthe spikes.

I claim:

I. A tie plate comprising:

a bottom planar surface for resting upon a tie;

a top planar surface spaced Apr. apart from the bottom surface forcarrying a rail, extending from one end to the 0pposite end of the tieplate, and cantedfrom one side to the other side of the tie plate at aslope of approximately 1 unit of rise to 40 units of run;

said top surface terminating at a raised abutment of each side of thetop surface having an inner side planar surface meeting the top planarsurface for restraining lateral movement of the rail;

said raised abutment having an outer side planar surface meeting thebottom surface for engaging a sidewall of a recess rabbetted in the tieto restrict lateral movement of the tie plate with respect to the tie;

said raised abutment having a top surface meeting the outer side planarsurface and the inner side planar surface of the raised abutment of thetie plate;

said top surface of the raised abutment having two slots cut therein atspaced locations on each side extending from the top surface of theraised abutment to the bottom 50 planar surface, the slots on each sidebeing diametrically opposed and each slot extending from the outer sideplanar surface to the inner side planar surface of the raised abutmentwhereby spikes may be disposed in the slots, and driven into the tie tohold the rail, the tie plate, and the tie together as a unit; and

said tie plate being comprised of a high density polyethylene havingapproximately 2% percent of a carbon black filler.

2. A tie plate comprising:

a right angled parallelepiped having a flat bottom surface for restingupon a tie and having an upper surface spaced apart from the bottomsurface;

a recess in the upper surface for carrying a rail, extending; from oneend to the opposite end of the tie plate and; defining a planar surfacethat is canted from one side to;

the opposite side at the slope of approximately 1 unit of rise to 40units of run with respect to the bottom surface whereby shoulders areprovided at each side of the right angled parallelepiped;

said shoulders providing an inner side surface contiguous with theplanar surface of the recess for restricting the lateral movement of therail and also providing an outer side surface contiguous with the flatbottom surface;

said tie plate being disposable into a recess rabbetted on the tie whichrecess has sidewalls engageable by the outer side surface of theshoulders forrestricting lateral movement of the tie plate;

two slots cut in each shoulder at spaced locations on each side, theslots on each side being diametrically opposed and each slot extendingfrom the edge of the plate to the recessed surface of the tie platewhereby spikes may be disposed in the slots and driven into the tie tohold the rail, the tie plate and the tie together a unit;

said tie plate being composed of a high density polyethylene beingcharacterized by the following physical properties:

Tensile strength (yield)300048000 p.s.i. Percent elongation atbreak65230 percent. Stiffness modulus G1 specimen)105,000150,000

p.s.i. Impact strength (Izod)1.515.0 ft.-lbs. per inch.Density-0.9410.965 gms./crn.

3. The tie plate of claim 1 wherein the high density' polyethylenehaving approximately 2% percent of a carbon 4. A tie plate comprising:

a right right angle parallelpiped having a flat bottom surface forresting upon a tie and having an upper surface spaced apart from thebottom surface;

a recess in the upper surface for carrying a base portion of a railextending from one end to the opposite end of the tie plate and defininga planar surface that is spaced a minimum distance of one-fourth inchfrom the flat bottom surface and that is canted from one side to theopposite side at the slope of approximately one unit of rise to 40 unitsof run with respect to thebottom surface whereby shoulders are providedat each side of the right parallelepiped having a minimum width ofseven-eighth inches;

said shoulders providing an inner side surface meeting the planarsurface of the recess having a depth into the tie plate equal to theheight of the base portion of the rail for restricting lateral movementof the rail and also providing an outer side surface of the shouldersfor restricting lateral movement of the tie plate with respect to thetie;

two slots cut in each shoulder at spaced location of 3% inches from thecenter to center of each slot, the slots on each side beingdiametrically opposed and spaced apart by 6% inches from center tocenter of each slot; each of said slots extending from the edge of thetie plate to the recessed surface of the tie by a distance ofseven-eighth inches whereby spikes may be driven into the tie to holdthe rail, the tie plate and the tie together as a unit; and

said tie plate being composed of a high density polyethylene havingapproximately 2 /2 percent by weight of carbon black filler which ischaracterized by the following physical properties:

Tensile strength (yield)3500 p.s.i. Percent elongation at brealr250percent. Stifiness modulus ($1 specimen)10o,000 p.s.i. Impact strength(Izod)-3.0 ft.-lbs. per inch. Density0.965 gms'. per cc.

Abrasion-20 mg. per 1000 cycles.

522 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Pacen: No- 55Dated December 1, 1970 Inventor(s) Charles J. Pennino It is certifiedthat error appears in the above-identified pate: and that said LettersPatent are hereby corrected as shown below:

In Claim 2, line 21 "Tensile Strength (yield) 5ooo-h8ooo psi" shouldread Tensile Strength (yield) $000-$800 psi SAME?) AND SEALED MR9 M AmenEdwuduflewhor. Ir. WILLIAM E. saaumm, JR.

Gomisaioner of Patents Attestmg Of

